leavitt



(No Model.)

4 SheetsSheet 1. P. M. LEAVITT.

DROP HAMMER.

Patented Sept. 28, 1886.

r. Washlngton. D. C.

(No Model.) 4 Sheets-Sheet 2. P. M. LEAVITT DROP HAMMER.

Patel 13d Sept. 28 1886.

/ VENTOR W/T/YEJGES- (No Model.) 4 Sheets-Sheet 3.

' F. M. LEAVITT.

DROP HAMMER. No. 350,007. Patented Sept. 28, 1886.

N PETERS. Phominhngraphur. Wnshmghzn, n. c.

' 1 4 Sheets-Sheet 4. P. M. LEAVITT.

(No Model.)

DROP HAMMER.

No. 350,007. Patented Sept. 28, 1886.

N PEYERS. Phnln Lllhngnlplhen Washmglon. n. c.

NITED STATES FRANK M. LEAVITT, OF BROOKLYN, BLISS COMPANY,

PATENT Erica.

NEV YORK, ASSIGNOR TO THE E. \V.

OF SAME PLACE.

DROP-HAMMER.

BYBKCEFICATION forming part of Letters Patent No. 350,007, dated September 28, 1886.

Application filed April 23, 1886.

T all whom, it may concern:

Be it known that l, FRANK M. LEAVITT, a citizen of the United States, residing at the city of Brooklyn, county of Kings, and State of New York, have invented an Improvement in Dropllammers or Drop-Presses; and I do hereby declare thatthc followingis a full,clear, and exact description ofthe same, reference be ing had to the accompanying drawings, forming part of this specification.

The invention relates to that type of drophammers or drop-presses in which the hammer or weight which is first raised and then dropped to strike the required blow by expenditure of the living force acquired during its fall is lifted by means of a flexible band or strap engaged by clamping friction-pulleys when the weight is being lifted and released from such engagement when the hammer or weight has been raised.

The principal objects of my present iuvention are to prevent the band or strap from wearing, as has heretofore been the case, by the action of friction upon the pulleys during V the falling of the weight, and to obviate the resistance to the fall of the weight due to such action of friction between the pulleys and strap or band, and thus secure a more free and effective fall of the weight, whereby an equally effective blow can be secured with a lighter hammer or a more effective blow from a hammer of the weight hitherto employed. A collateral purpose is also economy ofpower in driving this class of machines.

The construction and operation of my invention will fully appear from the following de scription and the drawings, of which Figure 1 is a front view with a medial portion broken out to permit essential parts of the machine to be presented in larger size and more clearly than could be possible were the entire elevation attempted. Fig. 2 is a side elevation with a portion broken away. Fig. 3 is a plan view of the upper part of the machine. Fig. 4. is a section of the upper part of the machine, made on the line 00 m in Fig. 3. Fig. 5 is a side view of a modification of the improvement in which the principles of my invention are comprised. Fig. 6 is a sectional side View ofsuch modification.

A, Figs. 1, 2, 5, and 6, is the base of the Serial No. 199,872. (No model.)

1 machine, made in the usual manner for ho1ding the anvil or fiXGd swage or die it is intended to support in proper relation with the drop hammer B, each of which parts is pro vided with the usual or any approved attachments for holding the fixed die or swage in proper relation with the hammer and its die or swage, to insure the required precision in the application of the machine, the hammer sliding on vertical guideways B, formed on or attached to uprights C, bolted to the base A in the usual manner.

0 is the flexible band or strap which raises the hammer, and which is preferably made of 6 good leather belting, but is not limited to this material. The hand, strap, or belt 0 extends upward and passes over a pulley, 'D, thence downward between the pulley D and another pulley, E, and is tightly clamped or gripped between the pulleys D and E during the act of raising the hammer B, but released from the gripping action of these pulleys when the hammer drops by mechanism yet to be described. It is evident that during the act of falling the hammer would, unless prevented by special mechanism, drag the strap over the surface of the pulley l) in the opposite direction to the motion of the latter, and the friction produced by such dragging action would greatly increase the destructive wear upon the strap, and, like a brake, more or less retard the fall of the hammer, and as the living force, or Ms viva, 0f the hammer is a strict function of the velocity of its fall, increasing or diminishing as the square of said velocity, it requires but a slight diminution of the velocity to notably reduce the effect of the blow. I will now describe the mechanism by which these defects are obviated. The prime driver of the machine is the pulley F, Figs. 1, 2, 3, and 4c, in the example herewith given in these figures, to which pulley power may be trans mitted by an endless belt (not shown) from any driving-shaft; but, as will subsequently appear, this arrangement may be modified without alfecting the nature of my invention. I do not therefore limit myself to this precise mode of imparting prime motive power to the machine. The pulley F is keyed to a shaft,

G, which has fixed bearings at H, Figs. 3 and 4, in the example of my invention shown in IOO Figs. 1, 2, 3, and 4. On the end of the shaft G, opposite the pulley F, is a stout pinion, I, which meshes into a gear, J, keyed to the shaft K of the pulley D. The pulley D is keyed to the shaft K, and this shaft has its journalbearings at L in the ends of rock-bars or levers M. The rock-bars or levers M are keyed to a rock-shaft, N, which has its journal-bearings in bosses 0, formed upon or attached to the horizontal metal frame P, which forms a support for the pulleys, gears, shafts, levers, and other mechanism, and which may be supported by hangers Q, attached to the overhead beamsof a shop or building, orin any other suitable way supported in proper relation with the base A and its attachments. The rock-levers M are levers of the third order, or, being keyed to the shaft N, which acts as a fulcrum common to both of them and moving together for. the same object, they may be regarded as forming a single leverot' the third order, their purpose being to move the pulley D slightly toward or away from the pulley E, to effect the clamping or gripping of the band 0 between said pulleys or to release the band from such engagement, according as the lever or levers M are actuated by mechanism yet to be described. The lever or levers M are actuated by strong links R, pivoted to the levers M at about their middle, as shown at S. These links are bifurcated at the upper ends, where they are pivoted to the levers M, and at their lower ends they are fitted to small but strong eccentrics T, Figs. 2 and 4, which latter, when turned on their axes,actuate the links'R,which,

in their turn, apply power to the levers M,

between their common fulcrum N, to overcome the resistance at the pulley shaft K arising from the inertia and weight of the said pulley and its attachments, the friction of bearings, &c.,when said pulley is moved toward or away from the pulley E for the purpose of gripping or releasing the band, strap, or belt 0, as hereinbefore set forth. The eccentrics T are keyed fast to a rock-shaft, U, Figs. 2 and 4, which has its journal-bearings in the frame 1?. To the rock-shaft U is also keyed alever,'V, Figs. 2, 3, and 4, by which the shafts U and eccentries T are turned radially on their common axis whenever the lever is moved upward or downward. To the end of the lever Vremote from the shaft U is pivoted a tappet-rod, WV. Formed as an integral part of or bolted to the hammer or drop Bis an arm, X, Figs. 1, 2, and 4, having a hole in its outer extremity, through which the tappet-rod WV passes, and when the machine is in operation the arm X freely slides up and down on the tappetrod.

Bigidly clamped to the tappet-rod W by clamping-screws y are adjustable tappets Y, against which the arm X strikes, the upper tappet .being struck on the under side when the. hammer B rises, and the lower one being struck on the upper side when thehammer is dropped, the tappet-rod being thus alternately raised and forced downward to actuate the mechanthe levers M, impart to said levers andthe pul- 'ley D a slight radial movement toward the pulley E, the center of this radial movement being the center of the shaft N. This movement, though slight, is sufficient to tightly and firmly clamp the band or strapG between said pulleys, and the reverse movement, caused by the arm X striking the upper tappet, at once releases the strap from the clamping action of the pulleys. The pulleys are geared together in such mannerthat their circumferential motion is equal, and, as indicated by the arrows, the direction of their motion is such that when the strap is clamped, as described, between them their holding force, together with the friction of the strap onthe pulley D, is sufficient to raise the hammerB without the slipping of the belt, thus insuring a positive and certain action of the machine. In order now that when the tappet-rod is raised or lowered for clamping or unclamping the strap between the pulleys 1) and E it shall with certainty retain either of the positions named until it is required to take the other position, I make use of the following device: To the frame P are bolted at their lower ends two strong arches, Z, these arches being primarily for the support of other mechanism herei nafter'described. To the side of that one of these arches nearest the tappet-rod W, I pivot ata the brake-bar too 1), Figs. 1, 2, and 4. Abutting against the back of the brake-bar b is a spring, a, which forcibly presses said brake-bar against the convex end of the lever V. It will be seen that in passing either upward or downward the convex end of the lever V must press the brakebar I) back against the action of the spring 0, the brake-bar being thus made to-resist the lever-until such time as the end of said lever passes the horizontal position, and that this resistance to the motion of said leverwill keep the latter, and the tappet-rod connected with it, from moving by their own weight or by the jarring action of the machine until the action of the arm X upon the tappet Ychanges the positions of allthe' correlated parts employed for clamping the strap between the pulleys D and E and releasing the strap from such clamping action; butwhile I have thus described the particular construction and action. of a spring-brake for holding the lever V in position till the arm X engages one or other of the tappetsY, I do not confine myself to this precise construction, as other -methods of constructing, attaching, and applying a springbrake may be used without at all affecting the principle of my invention.

The principal object of the arches Z is to afford bearings for certain counterpoised rock- ]evers, with idler-pulleys at one end, which, when the strap or band C is released from the clamping action of the pulleys D and E, raise the belt from the surface of these pulleys to prevent the frictional resistance of the strap from retarding the fall of the hammer and from rapidly wearing out the strap. I do not, however, confine myself to the particular method, which I shall presently describe, for actuating the idler pulleys. The method shown is a preferable way of accomplishing the object sought; but the arrangement of the pulleys and their action remaining the same any other method of actuating them radially outward against the strap would be substantially carrying out the principles of my invention.

To the arched supports Z are attached horizontal round bars or shafts (7, Figs. 1, 2, 3, and 4, which act as fulcrum-bearings for rocklevers c, counterpoised at the ends of their outer arms, as shown at f. The levers e are fitted to turn on the round bars or shafts d,

. and their arms opposite the counterpoised arms have attheir extremities idler pulleys g, pivoted to the arms, as shown. These idlerpulleys have flanges i projecting from their rims at the outside to guide and retain the strap or belt O always in proper relation with their faces and the face of the pulley D. The strap or band C is made considerably broader than the face of the pulleyD, as shown in Figs. 1 and 4, projecting equally over each side of the rim of the pulley D, and the faces of the rims of the idler-pulleys 9 inside of the flanges i are just broad enough to occupy and extend across the portions of the strap C, which project laterally over the pulleys D. The pulleys 9, Figs. 2 and 3, are constructed with flanges like the pulleys 9, but their diameters are less. They are pivoted to the counterpoisedrock-levereatitsinner end,asshown, one above and one below the strap, where the latter passes between the clamping-pulleys D and E. The idler-pulleys g act as guides for the strap 0 to hold the latter always in proper relation with said clamping or gripping pulleys, and the lower of these two idlers acts also to hold the strap away from the perimeter of E when the drop-hammer B is effecting its blow, and, as aforesaid, I consider any substitution of springs for the counter poised rock-levers, or of weights acting through other mechanism upon the idler-pulleys to move the same outward against the strap, band, or belt as an equivalent of the counterpcised rocleshat't herein described asa means for effecting such movement.

Figs. 5 and 6 represent a modification of the invention, which, however, carries out the principles above enunciated, to wit, the clamping of a flexible band, strap, or belt between a pulley having fixed bearings and a pulley havin movable bearings, an arrangement of idler-pulleys in relation with a pulley having fixed bearings and a pulley having movable bearings, to relieve said flexible strap, band, or belt from friction on the surfaces of the clamping-pulleys during the fall of the drophammer, substantially as hereinbefore specified. In thismodification thepulley Eis the one provided with movable bearings in the end of the rock-lever c, and the counterpoise g, or an equivalent, acts upon the end of said rocklever opposite the pulley E to press the pullcy E toward the pulley l), for clamping the strap, band, or belt between said pulleys for raising the hammer B. In this example of my invention the driving-pulley F is keyed directly to the shaft K of the pulley D without intermediate gearing. The arrangement of counterpoised levers and flanged pulleys cf is substantially the same and for the same purposes as hereinbefore set forth in the example of the invention shown in Figs. 1, 2, 3, and t. The release of the strap, band, or belt from its engagementby the gripping or damp ing action of the pulleys D and E is effected in this modification, as in the example already described, primarily by the action of the arm X projecting from the hammer B upon the tappets Y or the tappet-rod \V; but there is a slight change in the mechanism by which the vertical upward and downward movement of the tappet-rod finally effects the alternate clamping and release of the strap, as follows: The n pperend of the tappet-rod IV, Figs. Sand 6, is formed with an enlargement, is. This enlargement is recessed in the upper part to form a socket, Z, for the reception, retention, and support of a spring, on. The end ofthe rocklever c" is flattened on the under side at a, or otherwise suitably adapted to the spring m. At 0, where the enlarged portion it of the .rod joins and is continuous with the lower part of the same, is an easy fillet, which, when the machine is in action, acts against the lower end of the brakebanb, which is pivoted to the side of one of the metallic arches Z in the same way as in the example of the invention shown in Figs. 1, 2. 3, and 4. This brake-bar has a function strictly analogous to that in Figs. 1, 2, 3, and 4, which is to hold up the tappet-rod when raised till the hammer has made its blow, in doing which the arm X acts upon the lower t'appet on said rod to pull the tappet downward. The downward motion of the tappet-rod brings the fillet 0 into action against the inwardly-curved end of the brake-bar 'b and forces the latter outward against the pressure of the spring a, which spring is therefore in function, also the analogue of the spring a in Figs. 1, 2, 3, and 4'. The brake-bar bhas on its inner side a shoulder, 0', which engages the under side of the end of the lever c to hold it up against the weight off, or an equivalent, when raised by the upward movement of the tappet-rod. The

ICO

spring m acts in this modification as a buffer to prevent shock between the rock-lever c and the upper end of the tappet-rod.

In either way of carrying out the invention the tappet-rod may be worked by hand-levers L, as indicated in Figs. 5 and 6. It will now be apparent that in action the band, strap, or belt will have frictional contact or engagement with the perimeters of the pulleys D and I E only when the hammer or drop is being raised, during which time said strap will be tightly clamped and held from slipping on said perimeters, and that when the hammer begins to fall the belt will be supported by the pulleys g or g and E, and instead of slipping over the surfaces of D and E in an opposite direction to the motion of the latter, thus to cause wear of the strap and frictional resistance to the descent of the hammer, the pulleys g or g and IE will turn freely on their axes and obviate such wear and resistance.

In the counterpoise f of the counterpoised lever e, which has at the opposite end the idlerfalling too far.

Having thus fully described my improvement, what I claim as my invention, and desire to secure by Letters Patent, is as follows:

1. In a drop-hammer, the combination, with a hoisting-pulley and hammer-head, of a belt attached to said hammer-head and passing over said pulley, and a series of idler-pulleys or rollers for taking the belt off the hoistingpulley preparatory to the fall of the hammerhead, whereby the loss of velocity due to friction is materially diminished and the force of the blow consequently increased, substantially as set forth.

.2. The combination, with the hoisting-put ley and hammer-head, of a drop-hammer and a belt attached to the hammer-head and passing over the hoisting-pulley, of a gripping or clutch'pulley for engaging said belt with said hoisting-pnlley, and movable idler-pulleys or rollers for taking the belt off the hoisting-pulley preparatory to the fall of the hammer,substantially as and for the purposes described.

3. The combination, with the hoisting-pulley and hammer-head in a drop-hammer, of a hoisting-belt wider than the face of said hoisting-pulley, and flanged idler-pulleys or rollers engaging the overhanging edges of said belt for disengaging said belt from the. hoistingpulley preparatory to the fall of the hammer, substantially as and for the purposes set forth.

4. In a drop-hamnieror drop-press, the comover the hoisting-pulley and attached to said harnmer-head, a friction or gripping roller or pulley, and mechanism operated by the hammer-head for effecting the gripping action of the friction-roller and hoisting-pulley, with a series of idler-pulleys for engaging the edges of the belt and lifting the belt off the hoisting pulley preparatory to the fall of the hammerhead, substantially specified.

5. In adrop-press ordrop-hammer, the combination, with a flexible strap, band, or belt for raising the hammer, and clamping-pulleys narrower than such belt, one of which is a driving-pulley having fixed bearings,the other having movable bearings for clamping such belt between said pulleys when the face of one of the pulleys is pressed toward the face of the other, of idlerpulleys arranged in relation with said clamping-pulleys,and provided with as and for the purposes movable bearings actuated by weights or their I equivalent in such manner as to press said idler-pulleys outward against the inside faces of the margins of said strap, band, or belt, which project laterally over the perimeter of the clamping-pulleys for receiving the'weight of such strap, band, or belt, and relieving it from frictional contact or engagement with said perimeter while the hammer or strap falls,substantiallyas and for the purpose specified. 4

6. The co1nbination,with clamping-pulleys, one having fixed and anotherhaving movable bearings for alternately clamping and releasing the strap, band, or belt which raises the hammer of adrop-press,.of a strap, band, or belt broader than the clamping-pulleys, and idler pulleys having movable bearings arranged in relation with said clamping-pulleys,

'said idler-pulleys being actuated by weights or of a drop-press, of a lever of the third order having the movable bearings of one of the clamping-pulleys at one extremity, and the fulcrum bearing or bearings at the other exsaid lever between said fulcrum-bearing and said movable bearin gs of the clamping-pulley, an eccentric with fixed. bearings fitted to a movable bearing in the other end of said linkbar, and a lever rigidly connected at one end to said eccentric and having its other end pivoted to a tappet-rod for actuating said eccentric, link-bar levers, and movable pulley in clamping and releasing such strap, band, or

ICC

tremity, of such lever, a link-bar pivoted to belt, substantially as and for the purposes specified.

S. The combination of the pulley E, having fixed journal-bearings, the pulley D, having movable journal-bearings, the lever or levers M of the third order having the movable bearings of the pulley D at one end and a fulcrum bearing or bearings at the other end, a link-bar R, pivoted to the lover or levers M between the fulcrum bearing or bearings of said lever and the movable bearings of the pulley D, an eccentric, T, having fixed bearings and fitted to a movable bearing in the end of said link-bar, not pivoted to the lever M, a lever, V, rigidly attached to the eccentric T at one end, the tappet-rod W, pivoted to the other end of thelever V, and the spring brake-bar b, pivoted to a support in relation with the end of thelever V, for holding the lever Vand the parts connected with it when moved by said tappetrod in a fixed position till again moved by the tappet-rod, substantially as and for the purposes specified.

9. The combination, with clamping or gripping pulleys, one having fixed and the other movable journal-bearings, a band, strap, or belt wider than said pulleys, attached to the drop or hammer of a drop-press, passing between said pulleys, for alternately lifting and dropping said hammer, and mechanism for effecting approach and retreat of the face of the pulley having movable journal-bearings toward or away from the pulley having fixed bearings for alternate clamping and release of said strap, band, or belt, of a series of idlerpulleys arranged in relation with the clamping-pulleys in a manner to bear against the inside of the margins of said strap, band, or belt, which project laterally over the faces of the clamping-pulleys, and counterpoised rocklevers for pressing said idler pulleys out against the inside of the projecting margins of the strap, constructed and operating substantially as herein described, and for thepurposes specified.

10. The combination of the strap C. at tached to the hammer or drop B, lever V, eccentric T, link-bar R, rock lever or levers M, movable clampingpulley D, pulley E, and the gears I and J, for causing the faces of the pulleys 1) and E to move with equal circumferential velocity, substantially as and for the pn rpose set forth.

11. The combination, with the rock-lever e, of the set-screwy, and stop w, forlimiting the movement of said lever, substantially as and for the purpose specified.

FRANK M. LEAVITT.

\Vitnesses:

JNo. E. GAVIN, LEICESTER ALLEN. 

